CN117470226A - Inertial measurement device and method for manufacturing inertial measurement device - Google Patents

Abstract

Provided are an inertial measurement device and a method for manufacturing the inertial measurement device. The inertial measurement device is provided with: a substrate having a bonding region; a cap; a sensor device housed in a resin package and disposed in a mounting region on the substrate in an internal space between the substrate and the cap; and a sealing material that bonds the cap and the substrate at the bonding region of the substrate, the bonding material being formed so as to surround the mounting region and having a communication hole that communicates the internal space with the outside, the sealing material blocking the communication hole.

Description

Inertial measurement device and method for manufacturing inertial measurement device

Technical Field

The present invention relates to an inertial measurement device and a method for manufacturing the same.

Background

An inertial measurement device including an inertial sensor module having an inertial sensor such as an acceleration sensor or an angular velocity sensor is known. The inertial measurement device is incorporated in various electronic devices, machines, or mobile bodies such as automobiles, and is used for monitoring inertial amounts such as acceleration and angular velocity.

For example, patent document 1 discloses a sensor unit including a sensor device having an inertial sensor resin-sealed by a sealing resin.

Patent document 1: japanese patent laid-open No. 2017-49122

If moisture enters the sealing resin from the outside, there is a case where stress of the sealing resin fluctuates. When the stress of the sealing resin fluctuates, the inertial sensor deforms, which may affect the measurement of the sensor device. That is, there is a need for an inertial measurement unit having reduced influence of moisture and excellent detection accuracy, and a method for manufacturing the same.

Disclosure of Invention

An inertial measurement device according to an aspect of the present application includes: a substrate having a bonding region; a cap; a sensor device housed in a resin package, the sensor device being disposed in a mounting region on the substrate in an internal space between the substrate and the cap; and a sealing material that bonds the cap and the substrate at the bonding region of the substrate, the bonding material being formed so as to surround the mounting region and having a communication hole that communicates the internal space with the outside, the sealing material blocking the communication hole.

The method for manufacturing an inertial measurement device according to one embodiment of the present application includes the steps of: applying solder paste to a mounting region of a substrate and a bonding pad in a bonding region surrounding the mounting region, the bonding pad having a recess portion serving as a communication hole; placing a sensor device in the mounting region; placing a cap on the joint region; reflow soldering is carried out on the substrate; and sealing the communication hole by welding.

Drawings

Fig. 1 is a plan view of an inertial measurement device according to embodiment 1.

Fig. 2 is a cross-sectional view of section b-b of fig. 1.

Fig. 3 is a perspective view of fig. 1 from the P-direction.

Fig. 4 is a flowchart showing a flow of a method for manufacturing the inertial measurement device.

Fig. 5 is a plan view showing one form of a substrate in a manufacturing process.

Fig. 6 is a cross-sectional view showing one form of a substrate in the manufacturing process.

Fig. 7 is a perspective plan view schematically showing a sensor device.

Fig. 8 is a cross-sectional view of the f-f section of fig. 7.

Fig. 9 is a sectional view of section g-g of fig. 7.

Fig. 10 is a diagram showing a change in output fluctuation due to the presence or absence of a sealing material.

Fig. 11 is a partial plan view of the periphery of the communication hole of the inertial measurement device according to embodiment 2.

Fig. 12 is an enlarged perspective view of the periphery of the communication hole.

Fig. 13 is a partial plan view of the periphery of the communication hole of the inertial measurement device according to embodiment 3.

Fig. 14 is an enlarged perspective view of the periphery of the communication hole.

Fig. 15 is a plan view of an inertial measurement device according to embodiment 4.

Fig. 16 is a plan view of an inertial measurement device according to a different embodiment.

Fig. 17 is a plan view of the inertial measurement device according to embodiment 5.

Fig. 18 is an exploded perspective view showing an inertial measurement unit according to embodiment 6.

Fig. 19 is a perspective view of a substrate.

Fig. 20 is a perspective plan view of the angular velocity sensor.

Fig. 21 is a cross-sectional view of section j-j of fig. 20.

Description of the reference numerals

1a: an electrode terminal; 1b: a 1 st bonding pad; 2. 2f: a 2 nd bonding pad; 2b: a concave portion; 3: a 3 rd bonding pad; 4: a communication hole; 5: a substrate; 5a: an upper surface; 5b: a lower surface; 6: a mounting area; 7: a junction region; 8: a cap; 8a: a cavity; 8b: a flange portion; 9: solder paste; 9a: a bonding material; 9b: a sealing material; 10: a substrate; 11: a resin; 12. 13: a 2 nd bonding pad; 12b: a concave portion; 12c: a connection part; 18: a cover body; 18a: a concave portion; 20: a substrate; 21. 22, 23: a concave portion; 25: a 1 st gyro sensor element; 26: a 2 nd gyro sensor element; 27: a 3 rd gyro sensor element; 30: a substrate; 31. 32, 33: a concave portion; 35: a 1 st acceleration sensor element; 36: a 2 nd acceleration sensor element; 37: a 3 rd acceleration sensor element; 38: a cover body; 38a: a concave portion; 41: a base plate; 44: a communication hole; 45: 1 st inertial sensor; 46: a 2 nd inertial sensor; 50: a sensor device; 61: a substrate; 62: a connector; 70: a housing; 70b: a concave portion; 71: a mounting terminal; 72: an opening portion; 77: a convex portion; 77a: an upper surface; 81: a cap; 81b: a flange portion; 81c: a communication hole; 92: a base; 93: a vibration arm for detection; 94: a connecting arm; 95. 96: a driving vibrating arm; 97: a metal bump; 100. 110, 120, 130, 140, 150: an inertial measurement unit; 200x, 200y, 200z: an angular velocity sensor; 201: vibrating the gyroscope sensor element; 202: a base; 203: a 1 st substrate; 203a: an upper surface; 203b: a lower surface; 204: a 2 nd substrate; 205: mounting terminals; 206: an engagement member; 207: a cover; 300: an inertia measurement unit; 65: a control IC; s1, S2 and S3: a storage space; SP: an inner space.

Detailed Description

Embodiment 1

* Schematic structure of inertial measurement device

Fig. 1 is a plan view showing a schematic configuration of an inertial measurement device. Fig. 2 is a cross-sectional view of section b-b of fig. 1.

First, a schematic configuration of an inertial measurement device 100 according to the present embodiment will be described with reference to fig. 1 and 2. In each drawing, the X-axis, the Y-axis, and the Z-axis are illustrated as 3 axes orthogonal to each other. In the present embodiment, the 1 st axis is the X axis, the 2 nd axis is the Y axis, and the 3 rd axis is the Z axis. In addition, a direction along the X axis is referred to as an "X direction", a direction along the Y axis is referred to as a "Y direction", and a direction along the Z axis is referred to as a "Z direction". The arrow tip side in each axial direction is also referred to as "positive side", the base side is referred to as "negative side", the Z-direction positive side is referred to as "upper", and the Z-direction negative side is referred to as "lower". The Z direction is along the vertical direction, and the XY plane is along the horizontal plane. The positive direction and the negative direction are also collectively referred to as X direction, Y direction, and Z direction.

The inertial measurement device 100 of the present embodiment is configured by the sensor device 50, the substrate 5, the cap 8, and the like.

The sensor device 50 is, for example, a 6-axis combination sensor including a 3-axis gyro sensor and a 3-axis acceleration sensor. The sensor element of each axis is manufactured by processing a silicon substrate using MEMS (Micro Electro Mechanical Systems: microelectromechanical system) technology. The sensor device 50 has a flat rectangular parallelepiped shape, and a plurality of electrode terminals 1a are provided on the lower surface thereof. In addition, the outer package of the sensor device 50 is molded with resin, the details of which will be described later.

The substrate 5 is a substantially rectangular substrate on a plane. In a preferred embodiment, a ceramic substrate formed by stacking a plurality of ceramic substrates is used. The upper surface 5a of the substrate 5 serves as a mounting surface. A plurality of mounting terminals 71 are arranged on a lower surface 5b (fig. 2) which is a surface opposite to the upper surface 5 a. The plurality of mounting terminals 71 are electrically connected to the corresponding electrode terminals 1a of the sensor device 50 via wiring lines and through holes, not shown. The inertial measurement device 100 is mounted on a substrate of a higher-level device such as an inertial measurement unit, which will be described later, through a plurality of mounting terminals 71. The substrate 5 is not limited to a ceramic substrate, and may be a rigid substrate having air tightness, for example, a glass epoxy substrate, a glass composite substrate, or the like.

As shown in fig. 2, a sensor device 50 and a cap 8 are mounted on the upper surface 5a of the substrate 5. Specifically, the sensor device 50 is disposed in the mounting region 6 at the substantially center of the upper surface 5a, and the cap 8 is disposed in the joint region 7 surrounding the mounting region 6.

The electrode terminal 1a of the sensor device 50 is bonded to the 1 st pad 1b as a pattern for mounting provided in the mounting region 6 through the bonding material 9 a. The bonding material 9a is solder. In other words, the 1 st pad 1b for mounting the sensor device 50 is provided in the mounting region 6.

The cap 8 is a metal cover member having a cavity 8 a. The cap 8 has a bathtub-like shape, and is surrounded by a flange portion 8b around a recess formed by the cavity 8 a. In a preferred embodiment, the cap 8 is formed by press working a brass plate member, and is plated with tin on the surface. The material of the cap 8 is not limited to brass, and other metals such as kovar may be used. In other words, the cap 8 is preferably a metal cap. Alternatively, the cap 8 may be formed of a ceramic material, and in this case, the metal pattern may be provided on the entire surface of the flange 8b to enable welding.

The flange portion 8b is bonded to the 2 nd pad 2 as a mounting pattern provided in the bonding region 7 of the substrate 5 by the bonding material 9 a. The bonding material 9a is solder. The sensor device 50 is housed within the internal space SP formed by the cavity 8a of the cap 8. The internal space SP corresponds to a housing portion of the sensor device 50.

As shown in fig. 1, the joint region 7 is a portion where the flange portion 8b of the cap 8 is placed on the upper surface 5a of the substrate 5, and is a ring-shaped substantially rectangular region surrounding the mounting region 6.

The 2 nd pad 2 is provided on the bonding region 7, but the apex portion at 1 is cut away. In other words, the 2 nd pad 2 is disconnected at the vertex portion. The cut-out portion becomes a recess 2b lower than the surrounding 2 nd pad 2. When the cap 8 is provided on the 2 nd pad 2 and bonded with the bonding material 9a (fig. 2), the communication hole 4 is formed between the flange portion 8b and the recess portion 2b. The height of the recess 2b is, for example, about 30 μm to 50 μm, which is the thickness of the 2 nd pad 2, but is not limited thereto, and may be any height as long as it functions as an air hole. In other words, a recess 2b serving as the communication hole 4 is formed in the cutout portion of the 2 nd pad 2. In addition, it is preferable that the joint region 7 has a curved portion including an apex, and the communication hole 4 is provided in the curved portion.

The communication hole 4 functions as an air hole that communicates the internal space SP of the cap 8 with the outside.

A 3 rd pad 3 is provided outside the communication hole 4. The 3 rd pad 3 is provided in an L-shape at one vertex portion of the substrate 5, opposite to the communication hole 4. The side of the 3 rd pad 3 facing the communication hole 4 becomes a curve along the opening of the communication hole 4.

Here, when the width of the recess 2b, which is a cutout portion of the 2 nd pad 2 corresponding to the communication hole 4, is the width d, and the length of the portion of the 3 rd pad 3 facing the communication hole 4 is the length L, the length L is set to 1.5 times or more and 5 times or less of the width d. This is to set a size suitable for the case where the sealing material 9b is disposed from the 2 nd pad 2 to the 3 rd pad 3 to block the communication hole 4.

* Sealing means of communication holes

Fig. 3 is an enlarged perspective view of fig. 1 from the P-direction.

Fig. 3 is an enlarged perspective view of the peripheral portion centered on the communication hole 4.

As shown in fig. 3, the communication hole 4 is formed between the recess 2b as the cutout portion of the 2 nd pad 2 and the flange portion 8b of the cap 8. The 2 nd pad 2 is bonded to the flange portion 8b by a bonding material 9 a. The bonding material 9a is solder.

As shown in fig. 3, the communication hole 4 is hermetically sealed by a sealing material 9b. In detail, the sealing material 9b is provided by soldering from the 2 nd pad 2 to the 3 rd pad 3. In fact, the sealing material 9b also extends to the flange portion 8b of the cap 8 due to the presence of wetting spread of the solder. In fig. 3, the bonding material 9a is shown by solid lines and the sealing material 9b is shown by broken lines in order to clarify the respective constituent parts, but in reality, the bonding material 9a and the sealing material 9b are integrated, and the flange portion 8b, the 2 nd land 2, and the 3 rd land 3 are covered to seal the communication hole 4. In other words, the bonding region 7 includes a bonding material 9a and a sealing material 9b for bonding the cap 8 to the substrate 5. The sealing material 9b also blocks the communication hole 4.

The inner space SP (fig. 2) of the cap 8 is hermetically sealed by the sealing material 9b in a state of being filled with an inert gas. In a preferred embodiment, the airtight seal is performed in a state filled with nitrogen gas.

* Method of manufacturing inertial measurement unit

Fig. 4 is a flowchart showing a flow of a method for manufacturing the inertial measurement device. Fig. 5 is a plan view showing one form of a substrate in a manufacturing process. Fig. 6 is a cross-sectional view of the substrate in section c-c of fig. 5, corresponding to fig. 2.

A method of manufacturing the inertial measurement device 100 will be described.

In step S10, the substrate 5 is provided. As shown in fig. 5, the 1 st pad 1b, the 2 nd pad 2, and the 3 rd pad 3 are arranged on the substrate 5 in the initial state. In the preferred embodiment, each pad uses a wiring pattern in which gold plating is performed on a copper and nickel substrate, but the present invention is not limited thereto, and any wiring pattern may be used as long as it can be soldered. In other words, the 1 st pad 1b for mounting the sensor device 50 is provided in the mounting region 6, and the 2 nd pad 2 corresponding to the bonding material 9a (fig. 3) is provided in the bonding region 7. In a preferred embodiment, the substrate 5 is set in a dedicated jig in a state of a large-sized substrate in which a plurality of substrates 5 are bonded.

In step S11, solder paste 9 is applied to the 1 st pad 1b of the mounting region 6 and the 2 nd pad 2 of the bonding region 7 of the substrate 5. Specifically, as shown in fig. 6, a solder paste 9 is applied to the 1 st pad 1b and the 2 nd pad 2 as a bonding pad. In a preferred example, the application of the solder paste 9 is performed by screen printing using a mask having partial openings in contact with the 1 st pad 1b and the 2 nd pad 2. At this time, the solder paste 9 is not applied on the 3 rd pad 3. In addition, the coating may be performed using a dispenser. In other words, in the application step of the solder paste 9, the solder paste 9 is applied to the 2 nd pad 2 as a bonding pad in the mounting region 6 of the substrate 5 and the bonding region 7 surrounding the mounting region 6, and the 2 nd pad 2 has the recess 2b serving as the communication hole 4.

In step S12, the sensor device 50 is mounted on the substrate 5. Specifically, as shown in fig. 6, the electrode terminal 1a side of the sensor device 50 is placed on the substantially center of the upper surface 5a of the substrate 5 with its face down. The sensor device 50 is mounted face down to the substrate 5. In other words, in this step, the sensor device 50 is mounted on the mounting region 6.

In step S13, the cap 8 is placed on the substrate 5. Specifically, as shown in fig. 2, the cap 8 is placed on the 2 nd pad 2 with the flange 8b aligned. In other words, in this step, the cap 8 is placed on the joint region 7.

In step S14, the substrate 5 with the sensor device 50 and the cap 8 mounted thereon is subjected to a reflow process. In a preferred embodiment, the large-sized substrates in which the plurality of substrates 5 are bonded together pass through a reflow oven set to a predetermined temperature. As shown in fig. 1, the bonding material 9a is formed so as to surround the mounting region 6 and has a communication hole 4 for communicating the internal space SP with the outside.

Here, if the communication hole 4 is not provided, the cap 8 floats up and it is difficult to perform airtight sealing because there is no escape place when the air in the internal space SP of the cap 8 expands due to high temperature. In contrast, according to the inertial measurement device 100, the air that has expanded can escape from the communication hole 4, and therefore, the cap 8 does not float.

In step S15, the communication hole 4 is sealed with the sealing material 9 b. In detail, as shown in fig. 3, the communication hole 4 is sealed with a sealing material 9 by soldering from the 2 nd pad 2 to the 3 rd pad 3 so as to cover the communication hole 4. In a preferred embodiment, each substrate 5 is soldered one by one in a state of a large-sized substrate in a chamber filled with nitrogen gas. In other words, in this step, the communication hole 4 is sealed by welding. After the sealing process, the large-sized substrate was taken out of the chamber and cut into 1 small pieces, thereby completing the inertial measurement device 100.

* Summary of sensor device

Fig. 7 is a perspective plan view schematically showing a sensor device. Fig. 8 is a cross-sectional view of the f-f section of fig. 7. Fig. 9 is a sectional view of section g-g of fig. 7.

Fig. 7 is a perspective plan view of the sensor device 50 as viewed from the Z positive side. As shown in fig. 7, the sensor device 50 is constituted by the 1 st inertial sensor 45, the 2 nd inertial sensor 46, and the like, which are disposed on the base plate 41. The base plate 41 is a substrate on which 2 sensors are mounted.

As shown in fig. 8, the 1 st inertial sensor 45 has a base material 10, a cover 18, a 1 st gyro sensor element 25, a 2 nd gyro sensor element 26, and a 3 rd gyro sensor element 27. The 1 st gyro sensor element 25, the 2 nd gyro sensor element 26, and the 3 rd gyro sensor element 27 are housed in a housing space S1 formed by the base material 10 and the cover 18. The storage space S1 is an airtight space, and is preferably in a state closer to vacuum in a depressurized state.

In the 1 st inertial sensor 45, the 1 st gyro sensor element 25 detects an angular velocity around the X axis, the 2 nd gyro sensor element 26 detects an angular velocity around the Y axis, and the 3 rd gyro sensor element 27 detects an angular velocity around the Z axis. The 1 st gyro sensor element 25, the 2 nd gyro sensor element 26, and the 3 rd gyro sensor element 27 are gyro sensor elements manufactured by processing a silicon substrate using MEMS technology, and detect angular velocity from a change in capacitance between a movable electrode and a fixed electrode.

The substrate 10 has 3 recesses 21, 22, 23 formed therein, and the 1 st gyro sensor element 25, the 2 nd gyro sensor element 26, and the 3 rd gyro sensor element 27 are disposed on the substrate 10 so as to correspond to the recesses 21, 22, and 23, respectively. The concave portions 21, 22, and 23 function as relief portions for preventing the 1 st gyro sensor element 25, the 2 nd gyro sensor element 26, and the 3 rd gyro sensor element 27 from coming into contact with the base material 10, respectively.

The substrate 10 is a silicon substrate. The base material 10 may be a substrate formed of a glass material containing alkali metal ions, for example, pyrex (registered trademark) glass as a main material. The sensor structure is formed of a material such as polysilicon on the substrate 10 by a process according to a silicon semiconductor process. The sensor structures in the present embodiment are a 1 st gyro sensor element 25, a 2 nd gyro sensor element 26, and a 3 rd gyro sensor element 27.

The lid 18 has a recess 18a, and is joined to the base material 10 to form a storage space S1 in which the 1 st gyro sensor element 25, the 2 nd gyro sensor element 26, and the 3 rd gyro sensor element 27 are stored. The recess 18a is formed to face 3 recesses 21, 22, 23 of the base material 10. In the present embodiment, the cover 18 is formed of a silicon substrate. The substrate 10 and the cover 18 are bonded with glass frit or the like, and the sensor structure is hermetically sealed from the outside air. The above configuration of the sensor device is an example, and other examples are also possible. For example, the gyro sensor may be configured such that the driving unit is shared and only the detection unit is separated by an axis. The integrated circuits for controlling and detecting the 1 st gyro sensor element 25, the 2 nd gyro sensor element 26, and the 3 rd gyro sensor element 27 may be connected to the 1 st gyro sensor element 25, the 2 nd gyro sensor element 26, and the 3 rd gyro sensor element 27, or may be stacked on the 1 st gyro sensor element 25, the 2 nd gyro sensor element 26, and the 3 rd gyro sensor element 27.

Returning to fig. 7.

The 2 nd inertial sensor 46 is a 3-axis acceleration sensor that includes the 1 st acceleration sensor element 35, the 2 nd acceleration sensor element 36, and the 3 rd acceleration sensor element 37 and is capable of measuring accelerations of the detection axes in the X direction as the 1 st axis, in the Y direction as the 2 nd axis, and in the Z direction as the 3 rd axis. The 1 st acceleration sensor element 35, the 2 nd acceleration sensor element 36, and the 3 rd acceleration sensor element 37 are acceleration sensor elements manufactured using MEMS technology, and detect acceleration based on a change in capacitance between the movable electrode and the fixed electrode. In other words, the sensor device 50 includes the 2 nd inertial sensor 46 that detects a physical quantity different from the physical quantity detected by the 1 st inertial sensor 45.

As shown in fig. 9, the 2 nd inertial sensor 46 includes the base 30, the cover 38, the 1 st acceleration sensor element 35, the 2 nd acceleration sensor element 36, and the 3 rd acceleration sensor element 37. The 1 st acceleration sensor element 35, the 2 nd acceleration sensor element 36, and the 3 rd acceleration sensor element 37 are housed in a housing space S3 formed by the base material 30 and the cover 38. The storage space S3 is preferably an airtight space in which an inert gas such as nitrogen, helium, or argon is enclosed, and the use temperature is about-40 to 125 ℃, and is preferably approximately atmospheric pressure. However, the atmosphere of the storage space S3 is not particularly limited, and may be, for example, a reduced pressure state or a pressurized state. The substrate 10 and the substrate 30 are separate but may be integral. That is, the 1 st gyro sensor element 25, the 2 nd gyro sensor element 26, the 3 rd gyro sensor element 27, the 1 st acceleration sensor element 35, the 2 nd acceleration sensor element 36, and the 3 rd acceleration sensor element 37 may be formed on one substrate, for example, the substrate 10.

In the 2 nd inertial sensor 46, the 1 st acceleration sensor element 35 detects acceleration in the X direction, the 2 nd acceleration sensor element 36 detects acceleration in the Y direction, and the 3 rd acceleration sensor element 37 detects acceleration in the Z direction.

The substrate 30 has 3 recesses 31, 32, 33 formed therein, and the 1 st acceleration sensor element 35, the 2 nd acceleration sensor element 36, and the 3 rd acceleration sensor element 37 are disposed on the substrate 30 so as to correspond to the recesses 31, 32, and 33, respectively. The concave portions 31, 32, and 33 function as escape portions for preventing the 1 st acceleration sensor element 35, the 2 nd acceleration sensor element 36, and the 3 rd acceleration sensor element 37 from coming into contact with the base material 30, respectively.

The substrate 30 is a silicon substrate. The base material 30 may be a substrate formed of a glass material containing alkali metal ions, for example, pyrex (registered trademark) glass as a main material. The sensor structure is formed of a material such as polysilicon on the substrate 30 by a process according to a silicon semiconductor process. The sensor structures in the present embodiment are the 1 st acceleration sensor element 35, the 2 nd acceleration sensor element 36, and the 3 rd acceleration sensor element 37.

The lid 38 is formed with a recess 38a, and is joined to the base material 30 to form a storage space S3 in which the 1 st acceleration sensor element 35, the 2 nd acceleration sensor element 36, and the 3 rd acceleration sensor element 37 are stored. The recess 38a is formed to face the 3 recesses 31, 32, 33 of the base material 30. In the present embodiment, the lid 38 is formed of a silicon substrate. Thereby, the lid 38 and the base material 30 can be firmly joined by anodic bonding. The substrate 30 and the cover 38 are bonded with glass frit or the like, and the sensor structure is hermetically sealed from the outside air. The above configuration of the sensor device is an example, and other examples are also possible. The integrated circuit that realizes control/detection of the 1 st acceleration sensor element 35, the 2 nd acceleration sensor element 36, and the 3 rd acceleration sensor element 37 may be connected to the 1 st acceleration sensor element 35, the 2 nd acceleration sensor element 36, and the 3 rd acceleration sensor element 37, or may be stacked on the 1 st acceleration sensor element 35, the 2 nd acceleration sensor element 36, and the 3 rd acceleration sensor element 37.

Returning to fig. 7.

The sensor device 50 is a 6-axis combined sensor including a 1 st inertial sensor 45 as a 3-axis gyro sensor and a 2 nd inertial sensor 46 as a 3-axis acceleration sensor, and the periphery thereof is covered with a resin 11 as a resin package. The resin 11 is, for example, epoxy resin, and the housing of the sensor device 50 is resin-molded by the resin 11. In other words, the sensor device 50 is resin molded by the resin 11 as the 1 st package. The 2 nd inertial sensor 46 is housed in the 1 st package together with the 1 st inertial sensor 45.

Here, according to the verification by the inventors, it was confirmed that when the sensor device 50 is used in the as-is state, for example, if the humidity of the use environment fluctuates, moisture in an amount corresponding to the humidity after the fluctuation is adsorbed in the resin mold, and the residual stress in the resin 11 changes. This stress variation causes a fluctuation in stress to be stably applied to the sensor element, and there is a problem of fluctuation in sensor characteristics.

In the above description, the case where the sensor device 50 includes 6 sensor elements has been described, but the present invention is not limited to this, and at least the acceleration 3 axis and the angular velocity 3 axis may be detected, for example, the sensor elements may be 3 elements. In this case, for example, a 3-sensor element structure is provided which is composed of 2 acceleration sensor elements and 1 angular velocity sensor element. The 3 elements are configured to be combined by sharing the detection axis, and thus a sensor element capable of detecting 3-axis acceleration and 3-axis angular velocity is provided.

* Verification of moisture resistance

Fig. 10 is a diagram showing a change in output fluctuation due to the presence or absence of a sealing material, in which the horizontal axis represents time (hours) and the vertical axis represents output fluctuation (mgs).

A graph 55 shown in fig. 10 shows output fluctuations with time in the experimental environment of the inertial measurement unit 100 according to the present embodiment. The graph 56 shows the output fluctuation with time in the experimental environment of the inertial measurement unit of the comparative example, in which the sealing material 9b was not provided. In other words, in the inertial measurement device of the comparative example, the communication hole 4 is opened, and the internal space SP is in communication with the outside.

The experimental environment was set in the same posture with the inertial measurement device 100 of the present embodiment and the inertial measurement device of the comparative example in an environment having a humidity higher than normal temperature and normal humidity.

It is found that, in the graph 56 of the comparative example, the output fluctuation greatly increases in proportion to the passage of time. The offset fluctuation is presumed to be caused by the residual stress in the resin 11 being changed due to the external moisture being absorbed into the resin mold of the resin 11 of the sensor device 50 through the communication hole 4.

In contrast, according to the inertial measurement device 100 of the present embodiment, as shown in the graph 55, even when time passes, the output fluctuation is constant at about 1mG, and the output fluctuation is stable. In other words, it is found that the bias variation is small and the moisture resistance is stable.

As described above, according to the inertial measurement device 100 and the method of manufacturing the same of the present embodiment, the following effects can be obtained.

The inertial measurement device 100 includes: a substrate 5 having a bonding region 7; a cap 8; a sensor device 50 housed in the resin package and disposed in the mounting region 6 on the substrate 5 in the internal space SP between the substrate 5 and the cap 8; and a bonding material 9a and a sealing material 9b bonding the cap 8 to the substrate 5 in the bonding region 7 of the substrate 5, the bonding material 9a being formed so as to surround the mounting region 6 and having a communication hole 4 that communicates the internal space SP with the outside, the sealing material 9b blocking the communication hole 4.

Thereby, the internal space SP in which the sensor device 50 is housed is sealed in an airtight state by the sealing material 9 b. Therefore, the intrusion of moisture into the sensor device 50 from the outside can be prevented.

Therefore, the inertial measurement device 100 having excellent detection accuracy while reducing the influence of moisture can be provided. In other words, the inertial measurement device 100 having excellent moisture resistance and high reliability can be provided.

Further, the 1 st pad 1b on which the sensor device 50 is mounted is provided in the mounting region 6, the 2 nd pad 2 corresponding to the bonding material 9a is provided in the bonding region 7, the 3 rd pad 3 is provided outside the communication hole 4, and the sealing material 9b is arranged from the 2 nd pad 2 to the 3 rd pad 3.

Thereby, after the reflow process, the sealing material 9b can be provided by soldering from the 2 nd pad 2 to the 3 rd pad 3, and thus the communication hole 4 can be sealed.

When the width of the recess 2b, which is a cutout portion of the 2 nd pad 2 corresponding to the communication hole 4, is the width d, and the length of the portion of the 3 rd pad 3 facing the communication hole 4 is the length L, the length L is 1.5 to 5 times the width d.

Thus, when the sealing material 9b is disposed from the 2 nd pad 2 to the 3 rd pad 3, the communication hole 4 can be reliably plugged, and the soldering can be performed efficiently.

In addition, the cap 8 is a metal cap, and the bonding material 9a and the sealing material 9b are solder.

This can effectively block the communication hole 4 by welding.

Further, a recess 2b serving as a communication hole 4 is formed in the cutout portion of the 2 nd pad 2.

Thus, by attaching the cap 8 to the 2 nd pad 2, the communication hole 4 is formed between the flange portion 8b and the recess portion 2b.

Embodiment 2

* Different modes of inertial measurement unit-1

Fig. 11 is a partial plan view of the periphery of the communication hole of the inertial measurement device according to embodiment 2, and corresponds to fig. 1. Fig. 12 is an enlarged perspective view of the periphery of the communication hole, corresponding to fig. 3.

In the above embodiment, the case where the 2 nd pad 2 has the broken portion in a part of the ring shape has been described, but the configuration is not limited to this, and the configuration may be such that the communication hole is formed even if the broken portion is not provided. For example, the outer peripheral edge of the recess 12b of the 2 nd pad 12 may be connected by the connection portion 12 c. In the following, the same reference numerals are given to the same parts as those of the above embodiment, and overlapping description is omitted.

As shown in fig. 11, in the inertial measurement device 110 of the present embodiment, the 2 nd pad 12 is not disconnected at the corner, and the outer peripheral edge thereof is connected by the connecting portion 12 c. The connection portion 12c is provided outside the flange portion 8b of the cap 8, and a gap is provided between the flange portion 8b and the connection portion 12c in a plan view.

As shown in fig. 12, when the cap 8 is placed on the 2 nd pad 12, the gap becomes an opening of the communication hole 44. Thus, the communication hole 44 functions as an air hole for communicating between the outside and the internal space SP. The other configuration is the same as that described in embodiment 1.

In the inertial measurement device 110, the bonding material 9a is also formed so as to surround the mounting region 6 (fig. 11) and has a communication hole 44 that communicates the internal space SP with the outside, as shown in fig. 12, in a post-reflow configuration.

Further, when the communication hole 44 is sealed by welding, since the connection portion 12c is provided over the entire opening portion of the communication hole 44, the communication hole 44 is sealed more easily than in the case where the connection portion 12c is not provided.

In the above description, the connection portion 12c is provided at a position outside the flange portion 8b, but the structure is not limited to this, and for example, the connection portion 12c may be provided inside the flange portion 8 b. In this case, too, a gap is provided between the flange portion 8b and the connecting portion 12c in a plan view.

As described above, the inertial measurement device 110 according to the present embodiment can obtain the following effects in addition to the effects of the above-described embodiments.

According to the inertial measurement unit 110, the internal space SP in which the sensor device 50 is housed is sealed in an airtight state by the sealing material 9 b. Therefore, the intrusion of moisture into the sensor device 50 from the outside can be prevented.

Therefore, the inertial measurement device 110 having reduced influence of moisture and excellent detection accuracy can be provided.

Embodiment 3

* Different modes of inertial measurement unit-2 ×

Fig. 13 is a partial plan view of the periphery of the communication hole of the inertial measurement device according to embodiment 3, and corresponds to fig. 1. Fig. 14 is an enlarged perspective view of the periphery of the communication hole, corresponding to fig. 3.

In the above embodiment, the case where the communication hole 4 is provided between the recess 2b of the 2 nd pad 2 and the cap 8 has been described, but the configuration is not limited to this, and the communication hole may be formed in the cap. For example, in the inertial measurement device 120 of the present embodiment, the cap 81 is provided with a communication hole 81c. In the following, the same reference numerals are given to the same parts as those of the above embodiment, and overlapping description is omitted.

As shown in fig. 13, in the inertial measurement device 120 of the present embodiment, slit-shaped communication holes 81c are provided in the corners of the cap 81. The cap 81 has the same structure as the cap 8 of embodiment 1 except that it has a communication hole 81c. In the present embodiment, the 2 nd pad 13 has no notch, and is a bonding pad in which the corner is also closed in a ring shape with the same width as the straight line portion. As shown in fig. 14, a communication hole 81c is formed from an end of the flange portion 81b to a part of a side wall of the cap 81 main body across the flange portion 81 b. In other words, a communication hole 81c formed of a slit-shaped recess is formed in a position of the cap 81 corresponding to the 3 rd pad 3.

In the inertial measurement device 120, as shown in fig. 14, the bonding material 9a is formed so as to surround the mounting region 6 (fig. 13) and has a communication hole 81c for communicating the internal space SP with the outside.

When the communication hole 81c is sealed by welding, the sealing material 9b is provided so as to cover the communication hole 81c including a part of the side wall of the cap 81 main body.

As described above, the inertial measurement unit 120 according to the present embodiment can obtain the following effects in addition to the effects of the above-described embodiments.

According to the inertial measurement unit 120, the internal space SP in which the sensor device 50 is housed is sealed in an airtight state by the sealing material 9b. Therefore, the intrusion of moisture into the sensor device 50 from the outside can be prevented.

Therefore, the inertial measurement device 120 having reduced influence of moisture and excellent detection accuracy can be provided.

Embodiment 4

* Different modes of inertial measurement unit-3

Fig. 15 is a plan view of the inertial measurement device according to embodiment 4, and corresponds to fig. 1. Fig. 16 is a plan view of an inertial measurement device according to a different embodiment, corresponding to fig. 1.

In the above embodiment, the case where 1 communication hole 4 is provided has been described, but the present invention is not limited to this configuration, and a plurality of communication holes 4 may be provided. The communication hole 4 is not limited to being provided at the corner. In the following, the same reference numerals are given to the same parts as those of the above embodiment, and overlapping description is omitted.

As shown in fig. 15, in the inertial measurement device 130 of the present embodiment, 2 communication holes 4 are provided in the diagonal direction. Specifically, in addition to the communication holes 4 provided at the corners in the X positive direction and the Y positive direction, the communication holes 4 are also provided at the corners in the X negative direction and the Y negative direction. In other words, a plurality of communication holes 4 are provided in the joint region 7. The plurality of communication holes 4 are arranged to face each other with the mounting region 6 interposed therebetween. Other configurations are the same as those of the inertial measurement device 100 according to embodiment 1.

In the inertial measurement device 140 shown in fig. 16, 4 communication holes 4 are provided along the side of the 2 nd pad 2 f. Specifically, 2 communication holes 4 are provided in an aligned manner along one side of the 2 nd pad 2f in the Y positive direction. Further, 2 communication holes 4 are arranged along one side of the 2 nd pad 2f in the Y negative direction. In this way, the communication hole 4 may be provided in the straight portion. In other words, a plurality of communication holes 4 are provided in the joint region 7. The plurality of communication holes 4 are arranged to face each other with the mounting region 6 interposed therebetween. The other configuration is the same as that of the inertial measurement device 100 of embodiment 1.

As described above, the inertial measurement units 130 and 140 according to the present embodiment can obtain the following effects in addition to the effects of the above embodiments.

According to the inertial measurement units 130 and 140, the internal space SP in which the sensor device 50 is housed is sealed in an airtight state by the sealing material 9 b. Therefore, the intrusion of moisture into the sensor device 50 from the outside can be prevented.

Therefore, the inertial measurement units 130 and 140 having reduced influence of moisture and excellent detection accuracy can be provided.

Embodiment 5

* Different modes of inertial measurement unit-4

Fig. 17 is a plan view of the inertial measurement device according to embodiment 5, and corresponds to fig. 1.

In the above embodiment, the case where 1 sensor device 50 is housed in the internal space SP has been described, but the present invention is not limited to this configuration, and a configuration where a plurality of sensor devices 50 are housed in the internal space SP may be adopted. In the following, the same reference numerals are given to the same parts as those of the above embodiment, and overlapping description is omitted.

As shown in fig. 17, in the inertial measurement device 150 of the present embodiment, 2 sensor devices 50 are housed in the internal space SP. In detail, the substrate 5 and the cap 8 are provided in a rectangular shape long in the X direction, and the internal space SP is also formed in a horizontally long rectangular shape, in which 2 sensor devices 50 are arranged in an aligned manner. The number of sensor devices 50 is not limited to 2, and may be plural. The communication hole 4 is provided at 1 at the corner in the X positive direction and the Y positive direction. As in embodiment 4, a plurality of communication holes 4 may be provided. The other configuration is the same as that of the inertial measurement device 100 of embodiment 1.

In the above, the case where 2 sensor devices 50 are accommodated in the internal space SP has been described, but the present invention is not limited to this, and any resin molded device may be used. For example, the 1 st inertial sensor 45, which is a 3-axis angular velocity sensor resin molded as 1 device, and the 2 nd inertial sensor 46, which is a 3-axis acceleration sensor resin molded as 1 device, may be arranged in the internal space SP.

As described above, the inertial measurement device 150 according to the present embodiment can obtain the following effects in addition to the effects of the above-described embodiments.

According to the inertial measurement device 150, the internal space SP in which the plurality of sensor devices 50 are housed is sealed in an airtight state by the sealing material 9 b. Therefore, the intrusion of moisture into the sensor device 50 from the outside can be prevented.

Therefore, the inertial measurement device 150 having reduced influence of moisture and excellent detection accuracy can be provided.

Embodiment 6

* Inertial measurement unit

Fig. 18 is an exploded perspective view showing the inertial measurement unit. Fig. 19 is a perspective view of a substrate.

The inertial measurement device 100 described in the above embodiment can be applied to the inertial measurement unit 300 used in a monitoring system of a building such as a bridge or an overhead track where high accuracy is required. The same reference numerals are given to the same parts as those of the above embodiments, and duplicate descriptions are omitted.

As shown in fig. 18, the inertial measurement unit 300 of the present embodiment includes a connector 62 for easy connection to a measurement device (not shown) in a higher-level monitoring system. The inertial measurement unit 300 is constituted by the case 70, the substrate 61, and the like.

The housing 70 is a case that covers and protects the substrate 61, and an opening 72 for exposing the connector 62 is formed on the upper surface thereof. The connector 62 is a plug-type (male-type) connector, and includes 2 rows of connection terminals.

A recess 70b for accommodating the substrate 61 on which the inertial measurement device 100 and the like are mounted is provided on the lower surface of the housing 70.

In a state where the substrate 61 is assembled in the recess 70b of the housing 70, for example, a female connector corresponding to the connector 62 can be connected from the opening 72.

As shown in fig. 19, the substrate 61 is a rigid substrate such as a glass epoxy substrate. The substrate 61 has a substantially octagonal shape in plan view, and a connector 62 is provided along one side thereof.

A plurality of electronic components including the inertial measurement device 100, the connector 62, the control IC 65, the angular velocity sensor 200z, the angular velocity sensor 200x, the angular velocity sensor 200y, the chip resistor, the chip capacitor, and the like are mounted on the substrate 61. The control IC 65 is mounted on the back surface of the substrate 61. The substrate 61 may be shared with the substrate 5. In this case, the sensor device 50 and the cap 8 may be mounted on the substrate 61, or the 1 st pad 1b, the 2 nd pad 2, and the 3 rd pad 3 may be formed on the substrate 61.

The control IC 65 is an MCU (Micro Controller Unit: microcontroller unit) and controls each part of the inertial measurement unit 300. The storage unit provided in the control IC 65 stores a program for defining the order and content of detecting acceleration and angular velocity, a program for digitizing detected data and writing the digitized data into packet data, incidental data, and the like.

The angular velocity sensor 200z is mounted on the surface (surface on the case 70 side) of the substrate 61. The angular velocity sensor 200Z is a gyro sensor that detects the angular velocity of the 1-axis in the Z-axis direction. As a preferred example, a vibrating gyro sensor is used, which uses quartz as a vibrator, and detects an angular velocity from a coriolis force applied to a vibrating object. The present invention is not limited to the vibrating gyroscope sensor, and may be applied to any sensor capable of detecting angular velocity. For example, a sensor using ceramics or silicon as a vibrator may be used.

The angular velocity sensor 200X is a gyro sensor that detects an angular velocity of 1 axis in the X axis direction, and is disposed on the side surface of the substrate 61 in the X axis direction so that the mounting surface is orthogonal to the X axis. The angular velocity sensor 200Y is a gyro sensor that detects an angular velocity of 1 axis in the Y axis direction, and is disposed on a side surface of the substrate 61 in the Y axis direction so that the mounting surface is orthogonal to the Y axis.

Fig. 20 is a perspective plan view of the angular velocity sensor. Fig. 21 is a cross-sectional view of section j-j of fig. 20.

Next, the structure of the angular velocity sensor 200z will be described. The angular velocity sensor 200x and the angular velocity sensor 200y are also configured in the same manner as the angular velocity sensor 200 z.

The angular velocity sensor 200z shown in fig. 20 includes a vibrating gyroscope sensor element 201. The vibrating gyroscope sensor element 201 is a gyroscope sensor element manufactured by processing a quartz substrate using a photolithography technique, and converts vibration of a detection vibrating arm into an electrical signal to detect an angular velocity. Further, quartz is used as a base material, and thus the temperature characteristics are excellent. Therefore, the gyro sensor element manufactured by using the MEMS technique is less susceptible to noise and temperature from the outside, and the detection accuracy is higher.

As shown in fig. 20 and 21, the angular velocity sensor 200z includes: a vibrating gyroscope sensor element 201; a base 202 made of ceramic or the like that houses the vibrating gyroscope sensor element 201; and a cover 207 made of glass, ceramic, metal, or the like.

The susceptor 202 is formed by stacking a plate-like 1 st substrate 203 and a frame-like 2 nd substrate 204. The base 202 has an upwardly open storage space S2. The storage space S2 in which the vibrating gyroscope sensor element 201 is stored is hermetically sealed in a depressurized state, preferably in a state closer to vacuum, by being joined to the cover 207 by a joining member 206 such as a seal ring.

A convex portion 77 protruding upward is formed on the upper surface 203a of the 1 st substrate 203 of the base 202, and the vibrating gyroscope sensor element 201 is electrically and mechanically fixed to the upper surface 77a of the convex portion 77 via a metal bump 97 or the like. Therefore, the vibrating gyroscope sensor element 201 can be prevented from contacting the 1 st substrate 203.

A plurality of mounting terminals 205 are provided on the lower surface 203b of the 1 st substrate 203 of the base 202. The mounting terminal 205 is electrically connected to the vibrating gyroscope sensor element 201 via a wiring not shown.

The vibrating gyroscope sensor element 201 has: a base 92 located in the central portion; a pair of detection vibrating arms 93 extending in the Y direction from the base 92; a pair of connecting arms 94 extending from the base 92 in the X direction so as to be orthogonal to the detection vibration arms 93; each pair of driving vibration arms 95 and 96 extends in the Y direction from the distal end side of each connecting arm 94 so as to be parallel to the detection vibration arm 93. The vibrating gyroscope sensor element 201 is electrically and mechanically fixed to the upper surface 77a of the protruding portion 77 provided on the base 202 via the metal bump 97 or the like at the base 92.

In the vibrating gyroscope sensor element 201, when the angular velocity ωz about the Z axis is applied in a state in which the driving vibrating arms 95 and 96 are bending-vibrated in the X direction in opposite phases, the coriolis force in the Y direction acts on the driving vibrating arms 95 and 96 and the connecting arm 94, and vibrates in the Y direction. The detection vibration arm 93 is caused to perform bending vibration in the X direction by this vibration. Therefore, the detection electrode formed on the detection vibrating arm 93 detects deformation of quartz due to vibration as an electrical signal, thereby obtaining the angular velocity ωz.

As described above, according to the inertial measurement unit 300 of the present embodiment, the following effects can be obtained in addition to the effects of the above-described embodiments.

The inertial measurement unit 300 includes, in addition to the inertial measurement device 100 having high moisture resistance and excellent reliability, high-precision angular velocity sensors 200x, 200y, and 200z using quartz as a vibrator.

Therefore, the inertial measurement unit 300 having excellent reliability and high accuracy can be provided.

Claims (10)

1. An inertial measurement device is provided with:

a substrate having a bonding region;

a cap;

a sensor device housed in a resin package, the sensor device being disposed in a mounting region on the substrate in an internal space between the substrate and the cap;

a bonding material and a sealing material which bond the cap to the substrate at the bonding region of the substrate,

the joint material is formed to surround the mounting area and has a communication hole that communicates the internal space with the outside,

the sealing material blocks the communication hole.

2. The inertial measurement unit according to claim 1, wherein,

a 1 st pad for mounting the sensor device is provided in the mounting area,

A 2 nd bonding pad corresponding to the bonding material is provided at the bonding region,

a 3 rd pad is provided outside the communication hole,

the sealing material is disposed from the 2 nd pad to the 3 rd pad.

3. The inertial measurement unit according to claim 2, wherein,

when the width of the notch of the 2 nd bonding pad corresponding to the communication hole is set to be the width d, and the length of the part of the 3 rd bonding pad opposite to the communication hole is set to be the length L,

the length L is 1.5 times or more and 5 times or less of the width d.

4. The inertial measurement unit according to claim 3, wherein,

the cap is a metal cap and is provided with a recess,

the bonding material and the sealing material are solder.

5. The inertial measurement unit according to claim 3, wherein,

a recess serving as the communication hole is formed in the cutout portion of the 2 nd pad.

6. The inertial measurement unit according to claim 2, wherein,

a recess serving as the communication hole is formed in a position of the cap corresponding to the 3 rd pad.

7. The inertial measurement unit according to claim 2, wherein,

the engagement region has a curved portion which,

the communication hole is provided in the curved portion.

8. The inertial measurement unit according to claim 2, wherein,

a plurality of the communication holes are provided in the joint region.

9. The inertial measurement unit according to claim 8, wherein,

the plurality of communication holes are arranged to face each other across the mounting region.

10. A method for manufacturing an inertial measurement device, comprising the steps of:

applying solder paste to a mounting region of a substrate and a bonding pad in a bonding region surrounding the mounting region, the bonding pad having a recess portion serving as a communication hole;

placing a sensor device in the mounting region;

placing a cap on the joint region;

reflow soldering is carried out on the substrate; and

the communication hole is sealed by welding.